TCP / UDP

TCP	UDP
Reliable data transfer	Unreliable data transfer
Flow control: sender won’t overwhelm receiver	No flow control
Congestion control: throttle sender when network is overloaded	No congestion control
Does not provide: timing, minimum throughput guarantee, security	Does not provide: timing, throughput guarantee or security
Connection oriented	Datagram oriented
Extensive error checking mechanism	Basic error checksum
With ACK segment	No ACK segment
Packets arrive in sequence	No sequencing
Slower than UDP	Faster than TCP
Retransmission of lost packets	No retransmission
SYN, ACK, SYN-ACK handshakes	No handshakes
Used by HTTP, HTTPS, FRP, SMTP	Used by DNS, DHCP, VoIP
Byte stream	Message Stream